Located at the bottom edge of the outflow orifice (6) of a steam distributor is a nozzle (10) which extends in the manner of a slit over practically the entire length of the outflow orifice (6). The edges (14, 15) limiting the nozzle orifice (13) laterally are acute-angled and sharp; the inner walls (18, 19) adjoining these edges are designed so that water droplets which possibly form are conveyed away downwards.Because of the sharp edge design, water droplets cannot form in the outflow region (13) of the nozzle. The outflowing steam which subsequently mixes with an air stream (5) is therefore free of water drops. The formation of water droplets on the inner walls (18, 19) adjoining the said edges is harmless, since these droplets are conveyed away downwards as a result of the inclination of the said walls.